Open contact matrix switch

ABSTRACT

An open contact matrix is disclosed having a printed wiring card as one of the basic elements thereof; the printed wiring card includes a plurality of fixed contacts and a corresponding plurality of movable contacts extending from the wiring card. A frame is provided for supporting an array of operating members, which are solenoid driven, for selectively moving an actuator above predetermined sets of movable contacts to close them on to their corresponding fixed contacts.

United States Patent 1 1 1111 3,863,044 McCormick 1 Jan. 28, 1975 [54]OPEN CONTACT MATRIX SWITCH 3,397,371 8/1968 Barnaby et al..., 335/112$445,795 5/1969 Holtfreter et ul. 335/1 I2 [751 Invent Mccmm'ckch'cag3,529,113 9/1970 Vazquez et al. 335/112 x "l 3.551631 12/1970 Vazquez etal. 200/175 3.662.301 5 1972 335/112 [731 d 3678,422 7/1972 Reimer335/112 Northlake, lll. I Primary Examiner-James R. Scott Flledl 3 J y 11973 Attorney, Agent, or FirmDavid W. Heid [21] Appl. No.: 380,432

Y [57] ABSTRACT [52] US CL 200/175 200/] R 335/112 An open contactmatrix is disclosed'having a printed [51] Int. Cl.. 0 01h 6 Holh 67/26wiring card as one of the basic elements thereoflthe of I I I I I l l n1 printed Wiring Catd lnClUdeS' a of fixed 200/177 "v" A 1 6 f contactsand a corresponding plurality of movable 335/106 l l3 contacts extendingfrom the wiring card. A frame is provided for supporting an array ofoperating mem- [56] Refetences Cited bers, which are solenoid driven,for selectively moving an actuator above predetermined sets of movable vUNITED STATES PATENTS contacts to close them on to their correspondingfixed 2,516.772 7/1950 Hickman 335/113 x contacts, 2942.068 6/1960McCarthy eta]... 200/175 3,157,753 ll/l964 K1866 200/13 11 Claims, 14Drawing Flgures PAIEM m2 8 1975 saw 2 OF 4 OPEN CONTACT MATRIX SWITCHBACKGROUND OF THE INVENTION This invention relates generally to a matrixarrangement for closing predetermined sets of contacts arranged in across coordinate array. In particular, the invention is directed to across coordinate switch useful in connecting speech paths in a telephoneswitching system. Switches of the type disclosed herein are sometimescommonly referred to as crossbar switches, and perform a switchingfunction in the modern automatic telephone switching systems.

Some of the earlier crosspoint switches, such as that disclosed in US.Pat. No. 3,445,795 issued May 20, 1969 to Holtfreter et al., employed anarrangement of select units and hold units, and to keep the selectedcrosspoint closed it is necessary to maintain current flow through thehold magnet assembly. It is undesirable in modern switching systems torequire that a holding current for each crosspoint be maintained duringthe connection. A more preferable switching technique is to providecrosspoint switches in which a voltage pulse or pulses are used to closeor open the cross points.

With this in mind, several crosspoint switches have been devised inwhich no holding current is required; merely a series of pulses are usedto actuate the crosspoint and it maintains its actuated condition untilfurther pulses are used to break down the connection. Crossbar switchesillustrative of this type of contact actuation and release areillustrated in, for example, US. Pat. No. 3,529,113 issued to Vazquez etal on Sept. 15, 1970. In this crossbar switch arrangement tightly woundcoil springs are used to provide connection at selected crosspoints. Asomewhat similar crossbar switch which employs a pulsed connection andrelease arrangement is shown in US. Pat. No. 3,643,053 issued to Grundigon Feb. 15, 1972. In the Vazquez patent the mobile contact member whichis being moved into engagement with the stretched spring, is also acoiled spring which extends upward from the printed circuit board.During the operation and release of the crosspoint in the Vazquezarrangements, the coils of the associated mobile contact element tend towear the select and connect bars during the operation and release sincethe spring is moving across the select and connect bar during theconnection and release. This problem has been recognized and in the US.Pat. No. 3,551,631, issued to Vazquez et al. on Dec. 29, 1970, anL-shaped opening is included in the switch in an attempt to reduce thewear of the driving teeth of the connection bar which would occur if themobile contact were allowed to return to its release position withoutthe benefit of the L-shaped guide. However, this L-shaped guidingopening does not eliminate the wear on the select and connect barsduring the opera tion of the crosspoints. A further disadvantage of theVazquez arrangements is that the contact area is limited. The contactwhich is being made between the movable spring member and the fixedspring member is in a point to point contact giving limited area.

SUMMARY oF THE INVENTION In the present invention a cross coordinateswitch is provided which allows the crosspoints to be made by includingon a printed circuit board the fixed and movable contacts, the movablecontacts preferably comprising flat spring members. These flat springmembers provide a greater area of contact surface and hence a betterconnection than that provided in the Vazquez or Grundig arrangementscited previously. In the present invention an actuator, having a camsurface for closing the movable contacts onto the fixed contacts, isslidably supported above the printed circuit board on a frame, and thecamming of the flat springs against the actuator during operation andrelease produces only minimal wear.

The actuator in the present invention includes an outwardly extendingarm with the finger extending upward from its feee end. A select andconnect bar are positioned on the frame above the actuator to cooperatewith the finger and with a proper sequence of operation of the selectand connect bars in cooperation with the finger, move the actuator froma first to a second position to operate the predetermined crosspoint.Preferably the select and connect bars are made from plastic material,as is the actuator, the arm and finger portions thereof and hence theoperation of the crosspoint produces very minimal wear on the select andconnect bars.

The cross coordinate matrix of the present invention is mounted on aplug-in printed circuit board which allows fast and simple replacementof the matrix if for some reason there should be a failure at any of thecrosspoints. On the printed circuit board is mounted a frame whichsupports a plurality of solenoids for operating individual ones of anorthogonal array of operat-' ing members. The frame also supports anactuator above each crosspoint on the printed circuit board. A cover isincluded over the frame and serves to prevent extraneous material fromentering the matrix and contaminating the switch crosspoints, and withflexible select and connect bars the cover serves to hold them intoplace on the upper surface of the frame. The cover also clamps thesolenoids firmly into place in the frame.

One of the objects of the present invention is to provide a crosspointmatrix mounted on the printed circuit board which may be easily removedand installed for operation in a telecommunication switching system.

Another object of the present invention is to provide a crosspointmatrix in which operation and release of the crosspoints produces onlyminimal wear on the switch components.

A further object of the present invention is to provide a self-latchingelectromechanical crosspoint switch in which a predetermined crosspointmay be actuated and released by applying momentary voltage pulses in theproper sequence to select and/or connect solenoids which operate theselect and connect bars of the predetermined crosspoint.

BRIEF DESCRIPTION OF THE DRAWING FIG. is an-exp'loded perspective viewof the major building blocks of the crosspoint matrix of the presentinvention. Part of the printed circuit board and cover portion of theswitch have been shown in phantom.

FIG. 2 is a top plan view of one of the crosspoints-of the presentinvention in which the select and connect bars have been eliminated tobetter illustrate the position of the actuator in the frame, theactuator being shown in the unoperated position.

FIG. 3 is a sectional view taken along the lines 3-3 of FIG. 2.

FIG. 4 is a sectional view taken along the lines 44 of FIG. 2.

FIG. 5 is a side view of a typical crosspoint when the actuator has beenmoved forward and the movable contact hasbeen cammed into touch with thefixed contact on the printed circuit board.

FIG. 6 is a top plan view of a typical crosspoint which includes theselect and connect bars in their normal position and the actuator andits associated parts in the unoperated position.

'FIG. 7 is a top plan view of a typical crosspoint in which the connectbar has been moved by its associated solenoid.

FIG. 8 is a top plan view of a typical crosspoint in which the selectbar for the crosspoint has been actuated.

FIG. 9 is a top plan view of a typical crosspoint showing the return ofthe connect bar to its original position and the movement of theactuator to a forward position.

FIG. 10 is a top plan view showing the release of the select bar whichcompletes the operational sequence for the crosspoint.

FIG. 11 is a top plan view of an alternative embodiment of an actuatormeans.

FIG. 12 is a sectional view taken along the lines 12l2 of FIG. 11.

FIG. 13 is an enlarged sectional view taken along the lines 13--13 ofFIG. 1.

FIG. 14 is a sectional view taken along lines 14-14 of FIG. 13.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will best beunderstood by reference to the drawing figures, wherein now referring toFIG. 1 it will be noted that the matrix switch includes a printed wiringboard 1 having groups of movable and corresponding fixed contact setsindicated by reference character 2. A portion of printed wiring board 1is shown in the phantom view and it should be understood that therewould be a continuing row and column configuration of movable and fixedcontact sets 2, and in this particular embodiment there would be eightrows and eight columns of contact sets 2. The movable and fixed contactsets 2 will be described in detail subsequently, however they areillustrated in FIG. 1 to give the proper perspective of theirarrangement on the printed wiring board 1. A second major portion of thematrix switch is the frame 3. An orthogonal array of operating membersare supported on frame 3, and as viewed in FIG. 1, those members alignedin the rows are called connect bars and are designated by referencecharacter 7. Connect bars 7 may be individually operated by connectsolenoids 6, one solenoid 6 being provided for each connect bar 7. In asimilar manner, a plurality of select solenoids 5- as supported on frame3 and are used to energize the plurality of select bars 4. The matrixswitch is arranged such that for each intersection of a select andconnect bar there is a corresponding movable and fixed contact set 2.The movable contact portion of the set is closed against its associatedfixed contact set by the movement of an actuator, which will be morefully disclosed in later drawing figures, from a first or rest positionto its second or operated position by the proper sequence of operationof the select bar 4 and connect bar 7 at the particular crosspoint. Itwill be noted in FIG. 1 that the fixed contacts 12 of the movable andfixed contact sets 2 are brought out to tabs 9 by circuit paths 10.Printed wiring board 1 is what is termed a double sided board andcircuit paths (not shown) on the opposite side of the board, are used tomake electrical connections from movable contacts 11 to tabs (not shown)on the other sides of the board. All of the movable contacts 11 areelectrically connected in common on a column basis as seen in FIG. 1,and all of the fixed contacts 12 are electrically connected in common ona row basis. Hence it will be appreciated that an electrical connectionmay be made from any row to any column by appropriately pulsing the rowand column solenoids which intersect at the desired crosspoint.

A suitable number of holes 13 are provided in printed wiring board 1 sothat self-tapping screws (not shown) may be passed from the underside ofprinted wiring board 1 through holes 13 to secure frame 3 rigidly toprinted wiring board 1. It will also be noted that cover 14 includesholes 15 so that similarly a self-tapping screw 16 may be passed throughhole 15 and secure the cover 14 over the top of frame 3. Frame 3includes a rim [7 which completely encircles the outer perimeter of theupper portion of frame 3, and serves to support cover 14 slightly abovethe orthogonal array of select bars 4 and connect bars 7. Select bars 4are slidably supported on floor 18 of frame 3 and connect bars 7 areslidably supported on the array of select bars 4.

In order to better understand the operation of an individual crosspoint,at this point your attention is directed to FIG. 2, which is a top planview of one of the crosspoints of the matrix switch shown in FIG. 1 withthe select and connect bars for that crosspoint removed so that it iseasier to see the remaining crosspoint actuation parts. First it will benoted that actuator 19 is slidably supported on the floor 18, acutator19 having been snapped into slots 20. Actuator 19 may be freely movedforward or back within slots 20. The total support arrangement foractuator 19 is better illustrated in later drawing figures. It will benoted that actuator 19 includes an arm 21 which extends from theactuator and is integral therewith, and further it will be observed thata pin 22 is included on the free end of the arm 21. An opening 23 isincluded in the floor 18 at the crosspoint so that the arm 21 and pin 22may freely move forward and back during the actuation of a crosspoint.During the operation of the crosspoint, the free end of arm 21 traversesfrom the free or unrestricted area, the position in which it isillustrated in FIG. 2, to the restricted area at the upper end ofopening 23. Arm 21 is molded as a part of actuator 19 and inherentlyincludes a bias which tends to force the pin 22 to the right as viewedin FIG. 2. The necessity of this bias will become apparent subsequentlywhen the operation of a typical cross-point is explained. A subfloor 24is included beneath the free end of arm 21 and pin 22. Subfloor 24 isjust slightly below the free end of arm 21 and pin 22 and serves toprevent any downward flexing of the arm 21 during the operation orrelease of the crosspoint.

Now referring to FIG. 3, which is an enlarged sectional view taken alongthe lines 33 of FIG. 2, there it will be seen that the major portion ofactuator 19 rests below the lower surface of floor 18. The two outeredges of actuator 19 extend upward in a pair of wings 25 which includetabs 26 on the free end thereof. With this arrangement, actuator 19 maybe inserted from beneath the floor 18 and upon the tabs 26 passingthrough the upper surface of floor 18 the tabs 26 retain the actuator 19in the slots 20. It will also be observed in FIG. 3 how the movablecontacts 11 extend from printed circuit board 1 upward and touch camsurface 19a of actuator 19. Also in FIG. 3 it will be observed that foreach movable contact 11 there is a fixed contact 12 on the printedcircuit board 1.

Now referring to FIG. 4, which is a sectional view taken along the lines44 of FIG. 2, it will be seen that with the actuator 19 in its rearwardposition, movable contact 11 is extending upward from printed circuitboard 1 into contact with cam surface 19a, but the free end of movablecontact 11 is not touching its associated fixed contact 12. During theproduction of the switch, the individual movable contacts 11 will beinserted into printed wiring board 1 so that the end 27 will extendthrough a plated through hole 28 in printed wiring board 1 and aconventional soldering technique will be employed to affix end 27 viasolder means to the plated through hole 28. For clarity the solder hasnot been shown in FIGS. 4 and 5. As is shown in FIG. 4, movable contact11 will, under its own spring bias, be normally upward and out ofcontact with fixed contact 12 when actuator 19 is in its rearwardposition.

The operated position of a typical crosspoint is illustrated in FIG. 5where it will be noted that actuator 19 has been moved forward so thatthe free end of arm 21 has moved into the restricted area of opening 23and cam surface 19a of actuator 19 has pressed movable contact 11 intoengagement with its corresponding fixed contact 12. It will be observedin FIG. 4 that a portion of movable contact 11 extends upward,substantially above the area of contact with cam surface 19a of actuator19 and then descends toward its associated fixed contact 12. With thisconfiguration when actuator 19 is moved forward, movable contact 11touches fixed contact 12 before the full stroke of actuator 19 iscompleted. Further movement of actuator 19 presses contact 11 down withgreater force against contact 12 and also imparts a sliding motionbetween the free end of contact 11 and fixed contact 12. This slidingaction is produced by the displacement of that portion of contact spring11 which initially extends above the area of contact with cam surface19a of actuator 19. When actuator 19 moves into the area formerlyoccupied by the upper portion of spring contact 11, the free end ofcontact 11 is forced to move to the left, as viewed in FIGS. 4 and 5,producing a wiping motion between the fixed and movable contacts whichgives a self-cleaning action to the contacts.

Your attention is directed to FIG. 6 which is an enlarged top plan viewof a typical crosspoint showing the actuator 19 in its rearward positionand select bar 4 and connect bar 7 in their unoperated positions. Itwill be noted that pin 22 of arm 21 extends upward adjacent toprojection 29 of select bar 4. Pin 22 extends further upward and througha somewhat U-shaped opening 30 in connect bar 7. It will be recalledthat the arm 21 of the actuator 19 includes a molded-in bias whichnormally positions pin 22 to the right, and with the select bars 4 inplace the pins 22 of each crosspoint tend to hold the select bars 4 intheir unoperated positions. With the crosspoint in its unoperatedcondition as shown in FIG. 6, pin 22 will be in the position as shown inFIG. 6, the connect bars 7 being normally held in this position by aspring (not shown in this FIG. however) individual to each of theconnect solenoids 6. Hence,

upon the operation of a connect solenoid 6 for example, the connect baris pulled downward as viewed in 5 FIG. 7 against the spring individualto the connect bar 7. During the operation of select bar 4, the selectsolenoid 5 individual to the operated select bar 4 must pull against thebias inherent in each of the arms 21 associated with the energizedselect bar 4.

It will be recalled from the foregoing that in order to operate acrosspoint actuator 19 must be moved from its rearward position asillustrated in FIGS. 2. 4 and 6 to its forward position as illustratedin FIGS. 5, 9 and 10. The sequence of operation of the select bar 4 andconnect bar 7 to operate a crosspoint is illustrated by the first stepwhich is shown in FIG. 7. In FIG. 7 it will be noted that connect bar 7is first moved as indicated by the arrow, by its associated connectsolenoid 6 against the spring force of that solenoid to the positionshown in FIG. 7. It will be noted that the pin 22 is now in line withthe upper leg of the U-shaped opening 30 and may be moved into the upperleg by select bar 4 and into trapping zone 30a. The next step in theoperational sequence is illustrated in FIG. 8 wherein select bar 4 ispulsed by its associated select solenoid 5 and moves pin 22 intotrapping zone 30a of the upper leg of U-shaped opening 30. At this pointthe operating pulse which has been applied to connect solenoid 6ceasesand connect bar 7 is then returned to the position shown in FIG. 9by the spring associated with the connect solenoid. In FIG. 9, it willbe noted, that upon release of the connect bar 7 the pin 22 which wasmoved into trapping zone 30a of connect bar 7 has been moved forwardwhich of course translates actuator 19 to its forward position andoperates the crosspoint. Now that pin 22 has been moved forward it is nolonger necessary for select bar 4 to be retained in its energizedposition since surface 31 of opening 23 retains pin 22 in trapping zone30a and hence the pulse to select solenoid 5 is ceased and select bar 4is returned to its neutral position by the bias of the remaining arms 21in this column of the crosspoint switch.

FIG. 10 shows the crosspoint in its operated position wherein select bar4 has been returned to its unoperated position. This completes theoperation of a typical crosspoint and it will be appreciated at thispoint that the crosspoint is closed and will remain closed withoutmaintenance of a holding current since the solenoids are now both intheir neutral or unenergized condition.

In order to release a crosspoint which has been operated, it is merelynecessary to apply a voltage pulse to the connect solenoid 6 whichcontrols the connect bar that intersects the crosspoint to be released.Upon .reenergizing the connect solenoid 6, connect bar 7 will move inthe direction indicated by the arrow. in FIG. 7 and in so doing willmove pin 22 and its actuator l9-to the unoperated position. During thereturn of the actuator 19 to the unoperated position the bias exhibitedby arm 21 will cause the free end of arm 21 to travel along surface 31of upper portion of opening 23 and hence pin 22 will be guided out oftrapping zone 30a and returned to the unrestricted area of opening 23and into the unoperated position as shown in FIGS. 2, 4 and 6. With theactuator 19, arm 21, and pin 22 in this unoperated position, it will beappreciated that any other crosspoint in the row containing connect bar7 may be actuated since with pin 22 in its normal position by virtue ofsubsequent reoperation of the connect bar 7, connect bar 7 will not movepin 22 and actuator 19 upon operation thereof since the base of theU-shaped opening 30 allows free and uninhibited movement about thosepins 22 which are not moved into the trapping zone 30a of the upper legof U-shaped opening 30.

An alternative arrangement for operating a crosspoint using a somewhatdifferent arm on the actuator means is illustrated in FIG. 11 which is atop plan view of an alternative embodiment of an actuator means. Asviewed in FIG. 11 it will be noted that actuator 32 includes anupstanding stud 33 which is a molded integral part of the actuator 32.Stud 33 includes a slot 34 for receiving one end of a spring 35. Withone end of spring 35 inserted into slot 34 the other end extends outwardfrom stud 33 in an arm portion 36, which it will be noted is biasedupward as viewed in FIG. 11. The end of spring 35 opposite stud 33 isterminated in a folded, upward extending portion 37. Portion 37 servesthe same function in this embodiment as does pin 22 in the previousembodiment. To better appreciate the configuration of this alternative,embodiment your attention is directed to FIG. 12 which is a sectionalview taken along the lines 12-12 of FIG. 11. Actuator 32 here again, aswas true with actuator 19, includes wings 38 which may be pushed upwardthrough floor 18 and snapped into the slots 20 for the crosspoints. Alsoas was true with the actuator 19, tabs 39 are included on the free endof the wings 38 to hold the actuator 32 into slidable engagement withfloor 18 once the actuator 32 has been snapped into position on floor18. Actuator 32 includes cam surface 32a which performs the samefunction as cam surface 19a of actuator 19. In order to hold spring 35firmly in place once it has been inserted into slot 34 of stud 33, atechnique called spin welding may be utilized to melt and flow theplastic material on the upper end of stud 33 downward onto the upperedges of spring 35; this flow of material is indicated in FIG. 11 byreference character 46. This flow could also be accomplished throughultrasonic welding or staking.

In FIG. 13, which is an enlarged sectional view taken along the lines13-13 in FIG. 1, the relationship between the solenoid 6 and connect bar7 is illustrated. Connect solenoid 6 is supported in the matrix switchby the combination of frame 3 and cover 14, which when held together asmentioned previously by screws 16, clamps the solenoid 6 into place.Each solenoid 6 includes a plunger 40, which is shown in FIG. 13 in itsforward position, which is normally retained in this forward position byhelical spring 41. It will be recalled from the foregoing that solenoidsdo not require separate springs in conjunction with the plunger (notshown) since the plunger associated with each select solenoid 5 is keptin its outward or unoperated position by the bias from arms 21 ofactuators 19. However, in all other respects solenoids 5 and theirassociated plungers are identical to solenoids 6 and plunger 40 in theiroperation and relationship within the frame 3. The free end of plunger40 is terminated in a circular section 42 which is of a larger diameterthan plunger 40 which is inserted into the solenoid 6. As can be seen inFIG. 13, the upper part of section 42 is fitted into a semicircularopening 43 in connect bar 7. This fit be- .tween section 42 and thesemicircular opening 43 allows the solenoid 6 to operate and releaseconnect bar 7. It will be noted that the forward travel of plunger 40 islimited by the lower portion of section 42, which by virtue of spring41, is forced into engagement with the wall section 44 of frame 3. Inorder to establish a predetermined stroke for the connect bars, anupward pro- 5 jection 45 from frame 3 has been molded as a part of frame3. This upper projection 45 determines the stroke of solenoid 6 sincethe lower portion of section 42 of plunger 40 will strike the projection'45 upon its rearward travel when solenoid 6 has been energized. Wallsection 44 stops the forward travel of plunger 40 and hence eliminatesthe impact of plunger 40 on the select and connect bars.

In a like manner, the stroke of select solenoids 5 are also determinedby a similar wall and upward projection (not shown) from frame 3 in thecorresponding positions relative to each of the select solenoids 5.Hence it will be appreciated that the maximum stroke of the select andconnect bars may be determined by merely molding into frame 3appropriately dimensioned wall portions.

FIG. 14 is a sectional view taken along the lines 14-14 of FIG. 13, andillustrates plunger 40, section 42 and their relationship with frame 3.Upward projection 45 from frame 3, connect bar 7, section 42 and uppersurface 18 of frame 3 are also illustrated.

What is claimed is:

1. A cross coordinate switching arrangement comprising:

a planar printed circuit board having thereon a plurality of fixed and aplurality of movable contacts extending from said board in engageablerelationship with said fixed contacts;.

a plurality of actuators slidably supported adjacent to said movablecontacts, said actuators including a cam surface engageable with saidmovable contacts and said actuators being movable in a planesubstantially parallel to the plane of said printed circuit board, forselectively camming said movable contacts into engagement with theirassociated fixed contacts;

and

an orthogonal array of operating members selectively engageable withsaid actuators and adapted to selectively move said actuator means froma first to a second position to thereby operate the movable contact atthe selected cross coordinate.

2. The switching arrangement as claimed in claim 1 including a framesecured to said printed circuit board for slidably supporting saidactuators and said operating members.

3. The switching arrangement as claimed in claim 2 wherein each saidactuator includes an arm having a finger extending from the free endthereof, and said frame includes apertures through which said fingersextend, each of said fingers being positioned for selective engagementwith the operating members of a predetermined coordinate of saidoperating members whereby a predetermined actuator may be moved fromsaid first to said second position by selective engagement of theoperating members with the finger of said predetermined actuator.

4. The switching arrangement as claimed in claim 3 wherein said apertureadjacent the free end of said arm includes a restricted and anunrestricted area.

5. The switching arrangement as claimed in claim 4 wherein each said armbiases its finger toward said unrestricted area.

6. The switch as claimed in claim wherein said frame includes a platformpositioned below the free end of said arms.

7. The switching arrangement as claimed in claim 1 wherein said movablecontacts are cantilever-mounted springs.

8. A coordinate switch comprising:

a planar printed circuit board having a plurality of fixed contactsthereon, and a plurality of movable contacts extending from said printedcircuit board for selective engagement with corresponding fixedcontacts;

a frame supported in spaced relationship above said printed circuitboard;

a plurality of actuator means slidably supported by said frame formovement in a plane substantially parallel to the plane of said printedcircuit board, each said actuator means including a cam surface forpressing an associated movable contact into engagement with itscorresponding fixed contact and each said actuator means including anarm having an upturned free end;

a plurality of select bars having projections engageable with said freeends of said actuator arms; and

a plurality of connect bars having U-shaped openings, including atrapping zone, for receiving said free ends of said actuator arms, saidselect bars being selectively operable to move their associated freeends of said arms into the legs of said U-shaped openings whereby uponmovement of one of said free ends into a trapping zone of a connect barsaid free end and hence the actuator may be moved by said connect bar,from a first to a second position to thereby operate the contactsassociated with said displaced actuator.

9. The coordinate switch as claimed in claim 8 including solenoid meanssupported by said frame said solenoid means being operably coupled toand individual to each said select and connect bar for selectivelymoving said select and connect bars.

10. The coordinate switch as claimed in claim 9 wherein each saidsolenoid means includes a plunger and said frame includes a stoppingsurface for limiting the stroke of said plungers.

11. The coordinate switch as claimed in claim 8 wherein said movablecontact includes a curved portion which extends above the contact areabetween said actuator and said movable contact whereby upon movement ofsaid actuator from said first to said second position said actuatordisplaces said curved portion and hence moves said free end of saidmovable contact downward and outward to produce a sliding movementbetween said fixed contact and said free end of said UNITED STATESPATENT OFFICE CERTIFICATE OF CORRECTION Patent No- 3863044 Dated January28, 1975 I MAURICE D. MC CORMICK It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 9, line 6, before 'Springs" add leaf Signed and sealed this 1stday of April 1975.

s 11;) Attest:

C. I'U-IRSI-XALL DAMN Commissioner of Patents and Trademarks RUTH C.I'LKSON :Xttesting Officer FORM PO-IOSO (10-59) USCOMM-DC OOB'IO-PBD0.5. GOVIIIIIINT PRINTING OFFICE 2 "Cl 0-Sli-ll4.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3863044Dated January 28, 1975 In nt D. MC

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 9, line 6, before "springs" add leaf Signed and sealed this 1stday of April 1975.

Attest:

C. I-IARSHALL D.-KNN Commissioner of Patents and Trademarks RUTH C.I-LKSON Attesting Officer F ORM PC4050 (10-69) USCOMM-DC 603164 69 u.s.covllmlinr rmu'rme OFFICE nu o-ale-au.

1. A cross coordinate switching arrangement comprising: a planar printedcircuit board having thereon a plurality of fixed and a plurality ofmovable contacts extending from said board in engageable relationshipwith said fixed contacts; a plurality of actuators slidably supportedadjacent to said movable contacts, said actuators including a camsurface engageable with said movable contacts and said actuators beingmovable in a plane substantially parallel to the plane of said printedcircuit board, for selectively camming said movable contacts intoengagement with their associated fixed contacts; and an orthogonal arrayof operating members selectively engageable with said actuators andadapted to selectively move said actuator means from a first to a secondposition to thereby operate the movable contact at the selected crosscoordinate.
 2. The switching arrangement as claimed in claim 1 includinga frame secured to said printed circuit board for slidably supportingsaid actuators and said operating members.
 3. The switching arrangementas claimed in claim 2 wherEin each said actuator includes an arm havinga finger extending from the free end thereof, and said frame includesapertures through which said fingers extend, each of said fingers beingpositioned for selective engagement with the operating members of apredetermined coordinate of said operating members whereby apredetermined actuator may be moved from said first to said secondposition by selective engagement of the operating members with thefinger of said predetermined actuator.
 4. The switching arrangement asclaimed in claim 3 wherein said aperture adjacent the free end of saidarm includes a restricted and an unrestricted area.
 5. The switchingarrangement as claimed in claim 4 wherein each said arm biases itsfinger toward said unrestricted area.
 6. The switch as claimed in claim5 wherein said frame includes a platform positioned below the free endof said arms.
 7. The switching arrangement as claimed in claim 1 whereinsaid movable contacts are cantilever-mounted springs.
 8. A coordinateswitch comprising: a planar printed circuit board having a plurality offixed contacts thereon, and a plurality of movable contacts extendingfrom said printed circuit board for selective engagement withcorresponding fixed contacts; a frame supported in spaced relationshipabove said printed circuit board; a plurality of actuator means slidablysupported by said frame for movement in a plane substantially parallelto the plane of said printed circuit board, each said actuator meansincluding a cam surface for pressing an associated movable contact intoengagement with its corresponding fixed contact and each said actuatormeans including an arm having an upturned free end; a plurality ofselect bars having projections engageable with said free ends of saidactuator arms; and a plurality of connect bars having U-shaped openings,including a trapping zone, for receiving said free ends of said actuatorarms, said select bars being selectively operable to move theirassociated free ends of said arms into the legs of said U-shapedopenings whereby upon movement of one of said free ends into a trappingzone of a connect bar said free end and hence the actuator may be movedby said connect bar, from a first to a second position to therebyoperate the contacts associated with said displaced actuator.
 9. Thecoordinate switch as claimed in claim 8 including solenoid meanssupported by said frame, said solenoid means being operably coupled toand individual to each said select and connect bar for selectivelymoving said select and connect bars.
 10. The coordinate switch asclaimed in claim 9 wherein each said solenoid means includes a plungerand said frame includes a stopping surface for limiting the stroke ofsaid plungers.
 11. The coordinate switch as claimed in claim 8 whereinsaid movable contact includes a curved portion which extends above thecontact area between said actuator and said movable contact whereby uponmovement of said actuator from said first to said second position saidactuator displaces said curved portion and hence moves said free end ofsaid movable contact downward and outward to produce a sliding movementbetween said fixed contact and said free end of said movable contact.